Question

Copper and Germanium are cooled from room temperature to $100K$. Then the resistance of

• A. Germanium decreases, Copper increases
• B. Germanium decreases, Copper decreases
• C. Germanium increases, Copper decreases
• D. Germanium increases, Copper increases

Answer 1

The correct option is C Germanium increases, Copper decreases

As we know that resistance of a conductor increases with increase in temperature whereas that of semiconductor decreases with increase in temperature.

Copper is a very good conductor and germanium is a semiconductor. Thus resistance of copper decreases but that of germanium increases when they are cooled from room temperature to $100K$.